NTE7047 Integrated Circuit TV Color Small Signal Sub System

Transcription

1 NTE7047 Integrated Circuit TV Color Small Signal Sub System Features: Vision IF Amplifier with Synchronous Demodulator Automatic Gain Control (AGC) Detector Suitable for Negative Modulation AGC Tuner Automatic Frequency Control (AFC) Circuit with Sample and Hold Video Preamplifier Sound IF Amplifier and Demodulator DC Volume Control or Separate Supply for Starting the Horizontal Oscillator Audio Preamplifier Horizontal Synchronization Circuit with Two Control Loops Vertical Synchronization (Divider System) and Sawtooth Generation with Automatic Amplitude Adjustment for 50Hz and 60Hz Transmitter Identification (Mute) Generation of Sandcastle Pulse Absolute Maximum Ratings: Supply Voltage (Pin7), V P = V V Total Power Dissipation, P tot W Operating Ambient Temperature Range, T A to +65 C Storage Temperature Range, T stg to +150 C Electrical Characteristics: (T A = +25 C, V P = V 7 6 = 12V, carrier 38.9MHz, negative modulation unless otherwise specified) Supplies Supply Voltage Range (Pin7) V V Supply Current (Pin7) I 7 At no input ma Start Current (Pin11) I 11 Note ma Start Voltage Horizontal Oscillator V V Start Protection Level V 11 I 11 = 12mA 16.5 V Note 1. Pin11 has a double function. When during switch on a current of 9mA is supplied to this pin, it is used to start the horizontal oscillator. The main supply can then be obtained from the horizontal deflection stage. When no current is supplied to this pin it can be used as a volume control.

2 Vision IF Amplifier (Pin8 and Pin9) Input Sensitivity (RMS Value) V 8 9 At 38.9MHz, Note µv At 45.75MHz, Note 2, Note µv Differential Input Resistance R 8 9 Note Ω Differential Input Capacitance C 8 9 Note 3 5 pf Gain Control Range G db Maximum Input Signal V mv Output Signal Expansion for 48dB V 17 Note 4 1 db Variation of Input Signal Video Amplifier (Note 5) Zero Signal Output Level V 17 Note V Top Sync Level V V Video Output Signal Amplitude V 17 Note V White Spot Threshold Level 5.7 V White Spot Insertion Level 3.8 V Video Output Impedance 25 Ω Internal Bias Current of Output Transistor I 17(int) ma (NPN Emitter Follower) Maximum Source Current I ma Bandwidth of Demodulated Output Signal B 5 7 MHz Differential Gain G 17 Note % Differential Phase Note deg. Video Non Linearity NL Note % Intermodulation f = 1.1MHz (Blue), Note db f = 1.1MHz (Yellow), Note db f = 3.3MHz (Blue), Note db f = 3.3MHz (Yellow), Note db Signal to Noise Ratio S/N V i = 10mV, Note db End of gain control range, Note db Residual Carrier Signal V mv Residual 2 nd Harmonic of Carrier Signal V mv Tuner AGC Minimum Starting Point Tuner Take Over (RMS Value) Maximum Starting Point Tuner Take Over (RMS Value) V 8 9(rms) 0.2 mv V 8 9(rms) mv Maximum Tuner AGC Output Swing I 5(max) V 5 = 3V 4 ma Output Saturation Voltage V 5(sat) I 5 = 2mA 300 mv Leakage Current (Pin5) I L 1 µa Input Signal Variation Complete Tuner V i db Control

3 Tuner AGC (Cont d) Minimum Voltage Tuner Take Over V 1 1 V Voltage to Switch on the X Ray Protection V 1 Horizontal output high resistance 0.8 V AFC Circuit (AFC Sample and Hold/Switch) AFC Switch Off Current I ma Output Current I 19 V 19 = 0V ma Leakage Current at Pin19 I LO 2 µa AFC Circuit (AFC Output) AFC Output Voltage Swing V 18 Note 12, Note V Available Output Current I ma Control Steepness 100 mv/khz AFC Output Voltage with AFC Off V V AFC Output Resistance R kω Measured With an Input Signal Amplitude = 150µV (RMS value) Output Voltage Swing V 18 Note V Control Steepness Note mv/khz Sound Circuit (Note 14) Input Limiting Voltage V 15 V o(max) = 3dB µv Input Resistance R kω Input Capacitance C 15 6 pf AM Suppression AMS db AF Output Signal (RMS Value) V 12(rms) Note mv AF Output Signal when Pin11 is used as a Starting Pin or Connected to V P (RMS Value) V 12(rms) f = 50kHz mv AF Output Impedance Z Ω Total Harmonic Distortion THD Note % Ripple Rejection RR Volume control 20dB; f k = 100Hz 35 db Output Voltage When Muted V V Output Level Shift due to Muting V 12 Volume control 20dB 0.5 V Signal to Noise Ratio S/N Note db Voltage with Pin11 Disconnected V V Current with Pin11 Short Circuited to GND I 11 1 ma Temperature Dependence of the Output Signal Amplitude V 12 T A = +20 to +65 C, 30dB volume control and voltage of Pin11 fixed, Note db Volume Control (Note 18) External Control Resistor R 11 Note kω Suppression Output Signal during OSS db Mute Condition

4 Horizontal Synchronization Circuit (Sync Separator) Required Sync Pulse Amplitude V 25 Note mv Input Current, Pin25 I 25 V 25 > 5V 8 µa Horizontal Synchronization Circuit (First Control Loop) V 25 = 0V 10 ma Holding Range PLL ± f Hz Catching Range PLL ± f Hz IF Input Signal at which the Time Constant V 8 9 Strong to weak 2.2 mv is Switched (RMS Value) Horizontal Synchronization Circuit (Second Control Loop) Control Sensitivity t d / t o Note Control Range t d 25 µs Controlled Edge Horizontal Synchronization Circuit (Phase Adjustment, via Second Control Loop) Control Sensitivity positive 25 µa/µs Maximum Allowed Phase Shift α ±2 µs Horizontal Synchronization Circuit (Horizontal Oscillator, Pin23) Free Running Frequency f fr R = 34.3kΩ, C = 2.7nF Hz Spread with Fixed External Components f 4 % Frequency Variation f fr V P = 9.5 to 13.2V 2 % Frequency Variation with Temperature TC Note Hz/ C Maximum Frequency Deviation at Start f fr 10 % of Horizontal Output Frequency Variation when Only Noise is Received f fr Note Hz Horizontal Synchronization Circuit (Horizontal Output) Output Limiting Voltage V V Output Voltage LOW V 26 I sink = 10mA V Maximum Sink Current I ma Duty Cycle Output Signal 46 % Rise Time of Output Pulse t r 260 ns Fall Time of Output pulse t f 100 ns Horizontal Synchronization Circuit (Flyback Input and Sandcastle Output, Note 22) Input Current Required During I ma Flyback Pulse Output Voltage During Burst Key Pulse V 27 8 V Output Voltage During Horizontal Blanking V V Output Voltage During Vertical Blanking V V Pulse Width, Burst Key Pulse t W 60Hz µs Pulse Width, Horizontal Blanking Pulse 50Hz µs Flyback Pulse Width

5 Horizontal Synchronization Circuit (Cont d) (Flyback Input and Sandcastle Output, Note 22) Vertical Blanking Pulse 50Hz divider in search window 21 lines 60Hz divider in search window 17 lines 50Hz divider in narrow window 25 lines 60Hz divider in narrow window 21 lines Delay Between Start of Sync Pulse at Trailing edge, 60Hz 9.3 µs the Video Output and the Burst Key Pulse Rising edge µs Horizontal Synchronization Circuit (Coincidence Detector) Voltage for Synchronized Condition V V Voltage for No Signal Condition V V Switching Level to Switch the Phase V V Detector from Fast to Slow Hysteresis Slow to Fast V V Switching Level to Activate the Mute V V Function (Transmitter Identification) Hysteresis Mute Function V 22 2 V Delay Time of Mute Release after Transmitter Insertion 300 µs Allowable Load on Pin22 10 µa External Video Mode V V Current at Pin22 I 22 V 22 = 0V 0.8 ma Vertical Circuit (Vertical Ramp Generator, Note 24) Input Current During Scan I 2 2 µa Discharge Current During Retrace I ma Sawtooth Amplitude (peak to peak value) V 2(p p) 1.9 V Interlace Timing of the Internal Pulses µs Vertical Circuit (Vertical Output, Note 24) Available Output Current I 3 V 3 = 4V 3 ma Maximum Output Voltage V 3 I 3 = 0.1mA V Vertical Circuit (Vertical Feedback Input, Note 24) Input Voltage, DC Component V V Input Voltage, AC Component (peak to peak value) V 4(p p) 1 V Input Current I 4 12 µa Internal Precorrection to Sawtooth t p 3 % Deviation Amplitude 50Hz/60Hz 2 % Temperature Dependence of the T A = +20 C to +65 C 2 % Amplitude Vertical Circuit (Vertical Guard, Note 24, Note 25) Active Switching Level at a Deviation with Respect to the DC Feedback Level: Guard Level LOW V 4 V 27 = 2.5V 2.1 V

6 Vertical Circuit (Cont d) (Vertical Guard, Note 24, Note 25) Active Switching Level at a Deviation with Respect to the DC Feedback Level: Guard Level HIGH V 4 V 27 = 2.5V 2.0 V Notes: Note 2. On set AGC. Note 3. The input impedance has been chosen such that a SAW filter can be applied. Note 4. Measured with 0dB = 450µV. Note 5. Measured at 10mV (RMS value) top sync input signal. Note 6. So called projected zero point; i.e. with switched demodulator. Note 7. White 10% of the top sync amplitude. Note 8. The differential gain is expressed as a percentage of the difference in peak amplitude between the largest and smallest value relative to the subcarrier amplitude at blanking level. The differential phase is defined as the difference in degrees between the largest and smallest phase angle. The differential gain and phase are measured with a DSB signal. Note 9. This figure is valid for the complete video signal amplitude (peak white to black). The non linearity is expressed as a percentage of the maximum deviation of a luminance step from the mean step, with respect to the mean step. Note10. The figures are measured at an input signal of 10mV (RMS value). Note 11. Measured with a source impedance of 75Ω. V out black to white Signal to noise ratio = 20 log V n(rms) at B = 5MHz Note12. The AFC control voltage is obtained by multiplying the IF output signal (which is also used to drive the synchronous demodulator) with a reference carrier. This reference carrier is obtained from the demodulator tuned circuit via a 90 degree phase shift network. The IF output signal has an asymmetrical frequency spectrum with respect to the carrier frequency. To avoid problems due to this asymmeterical signal the AFC circuit is followed by a sample and hold circuit which samples during the sync level. As a result the AFC output voltage contains no video information. The specified control steepness is without using an external load resistor. The control steepness decreases when the AFC output is loaded with two resistors between the voltage supply and GND. Note13. At very weak input signals the drive signal for the AFC circuit will have a high noise content. This noise input has an asymmetrical frequency spectrum which will cause an offset of the AFC output voltage. To avoid problems due to this effect a notch filter can be built in to the demodulator tuned circuit. The characteristics given for waek input signals are measured without a notch circuit, with a SAW filter connected in front of the IC (input signal such that the input signal of the IC is 150µV (RMS value). Note14. The sound circuit is measured (unless otherwise specified) with an input signal of V 15 of 50mV (RMS value), a carrier frequency of 5.5MHz at a f of 27.5kHz and AF frequency of 1kHz. The QL of the demodulator tuned circuit is 16 and the volume control is connected to the supply. The reference circuit must be tuned in such a way that the output is symmetrical clipping at maximum volume. Note15. The output signal is measured at a f = 7.5kHz and maximum volume control. Note16. The demodulator tuned circuit must be tuned at minimum distortion. Note17. Weighted noise, measured according to: CCIR 468. Note18. See also Note 1. The volume can be controlled by using a potentiometer connected to GND (value 10kΩ) or by means of a variable direct voltage. In the latter case the relatively low input impedance (Pin11) must be taken into account.

7 Notes (Cont d): Note19. The minimum value is obtained with a 1.8kΩ series resistor connected between Pin17 and Pin25. The slicing level can be varied by changing the value of this resistor (a higher resistance results in a larger value of the minimum sync pulse amplitude). The slicing level is independent of the video information. Note20. Frequency control is obtained by supplying a correction current to the oscillator RC netword. This is achieved via a resistor connected between the phase 1 detector output and the oscillator network. The oscillator can be adjusted to the correct frequency by: short circuit the sync separator bias network (Pin25) to the voltage supply. To avoid the necessity of a VCR switch, the time constant of the phase detector at strong input signals is sufficiently short to obtain a stable picture during VCR playback. During the vertical retrace period the time constant is even shorter so that VCR head errors are compensated for at the beginning of the scan. During weak signal conditions (information derived from the AGC circuit) the time constant is increased to obtain a good noise immunity. Note21. This figure is valid for an external load impedance of 82kΩ connected between Pin28 and the shift adjustment potentiometer. Note22. The horizontal flyback input and the sandcastle output have been combined on Pin27. The flyback pulse is clamped to a level of 4.5V. The minimum current to drive the second control loop is 0.1mA. Note23. The in sync/out of sync and transmitter identification have been combined on Pin22. The capacitor is charged during the sync pulse and discharged during the time difference between gating and sync pulsxe. Note24. The vertical scan is synchronized by means of a divider system, therefore no adjustment is required for the ramp generator. The divider detects whether the incoming signal has a vertical frequency of 50Hz or 60Hz and corrects the vertical amplitude. Note25. To avoid screenburn due to a collapse of the vertical deflection, a continuous blanking level is inserted into the sandcastle pulse when the feedback voltage of the vertical deflection is not within the specified limits. Note26. These figures are based on sampled tests. AGC Takeover/X Ray Protection Vert Ramp Generator Vertical Drive Vertical Feeback Tuner AGC GND V CC Volume Control/Start Horiz OSC Audio Output Pin Connection Diagram Phase 2 Detector Sandcastle Output/Horiz Flyback Input Horizontal Drive Sync Separator 24 Phase 1 Detector 23 Horizontal OSC Coincidence Detector Vision Demod Tuned Ckt Vision IF Input Vision IF Input 9 20 Vision Demod Tuned Ckt IF AGC AFC S/H, AFC Switch AFC Output Video Output Sound Demod GND Sound IF Decouple Sound IF Input

8 (37.32) Max.540 (13.7).250 (6.35).100 (2.54) (33.02).122 (3.1) Min.600 (15.24)